Chain Fatty Alcohols Research Articles

Bioaccessibility of avocado polyhydroxylated fatty alcohols

Avocado-derived polyhydroxylated fatty alcohols (PFAs), such as avocadene and avocadyne, have been recently identified as potent modulators of mitochondrial metabolism which selectively induce leukemia cell death and reverse pathologies associated with diet-induced obesity. However, avocadene and avocadyne bioaccessibility from avocado pulp is not reported; hence, this study aims to investigate if these PFAs are bioaccessible. Dynamic (TNO dynamic intestinal model-1 (TIM-1)) and static in vitro digestion of lyophilized Hass avocado pulp powder shows lipolytic gastrointestinal enzymes led to appreciable bioaccessibility of avocadene (55%) and avocadyne (50%). Furthermore, TIM-1 digestion of a 1:1 ratio of pure avocadene and avocadyne (avocatin B or AvoB) crystals formulated in an oil-in-water microemulsion has on average 15% higher bioaccessibility than the avocado pulp powder demonstrating both dosage forms as potential dietary sources of avocado PFAs. This research provides the impetus for further research on the nutritional significance of dietary long chain fatty alcohols.

Characterization and identification of an archaeological “lacquer” pipe

A pipe with red coating on the surface was excavated from an archaeological site in Sweden, which is supposed to be a lacquer ware imported from China due to the admiration and pursue of lacquer wares from Asia by Europeans during sixteenth to eighteenth centuries. However, materials such as shellac and resins were often used to imitate lacquer during that time in Europe. To determine whether the pipe was Chinese lacquer ware or not, attenuated total reflection of fourier transform infrared spectroscopy (ATR-FTIR), thermally-assisted hydrolysis and methylation pyrolysis gas chromatography-mass spectrometry (THM-Py-GC/MS) were conducted. The detection of significant amount of aleuritic acid, laccijalaric acid, laccishellolic acid, shellolic acid and jalaric acid represents that shellac is the main material used for the pipe coating rather than Chinese lacquer. Long chain fatty alcohols were found in the sample, indicating that the shellac is un-dewaxed. In addition, pine resin and turpentine were also found as additives in the pipe coating. Furthermore, pigments in the coating were determined as cinnabar and carbon black by scanning electron microscopy with element energy dispersive spectroscopy (SEM–EDS) and Raman spectroscopy. The results could definitely support the conservation of the pipe, and also provide the evidence of the cultural exchange between Europe and Asia.

Characterisation of fatty acyl reductases of sunflower (Helianthus annuus L.) seed

Long and very long chain fatty alcohols are produced from their corresponding acyl-CoAs through the activity of fatty acyl reductases (FARs). Fatty alcohols are important components of the cuticle that protects aerial plant organs, and they are metabolic intermediates in the synthesis of the wax esters in the hull of sunflower (Helianthus annuus) seeds. Genes encoding 4 different FARs (named HaFAR2, HaFAR3, HaFAR4 and HaFAR5) were identified using BLAST, and studies showed that four of the genes were expressed in seed hulls. In this study, the structure and location of sunflower FAR proteins were determined. They were also expressed exogenously in Saccharomyces cerevisiae to evaluate their substrate specificity based on the fatty alcohols synthesized by the transformed yeasts. Three of the four enzymes tested showed activity in yeast. HaFAR3 produced C18, C20 and C22 saturated alcohols, whereas HaFAR4 and HaFAR5 produced C24 and C26 saturated alcohols. The involvement of these genes in the synthesis of sunflower seed wax esters was addressed by considering the results obtained.

Organic Extraction, Purification and Evaluation of Long Chain Fatty Alcohol from Saccharum officinarum of Sugar Refinery Waste for Human Wellness

The current study has explored an extraction and purification method for 1-octacosanol from sugarcane waste, commonly known as press mud, through the application of SCFE by the unique concept of solid-solid and liquid-liquid extraction which increases content and decreases impurity which is an extra advantage at purification stage by help of green solvent instead any carcinogenic solvent, which reduce process time, increase content and environment friendly. The isolated compounds were characterized by gas chromatography-flame ionization detection, which shows 50% content of octacosanol in the final product. Novel refinement technique through hot ethanolic reflux method has substantially increased the octacosanol assay to ≥ 50% with more than 67% purity from the crude wax assay of 26% obtained by the current method of extraction. The identity of said compound was further authenticated by X-ray diffraction (XRD), Diffraction scanning calorimetry (DSC) and FTIR studies. The purity of the octacosanol obtained was ≤70% and the conversion recovery of octacosanol was 80.04% by the reflux method, thereby representing the simplicity of the above process for industrial feasibility. The current process represents a value addition liquid-liquid supercritical extraction with a time-saving, cost-effective, reproducible, newer, green, safe, and sustainable technology valorizing sugarcane waste for a high-end nutraceutical

A simple method to isolate fatty acids and fatty alcohols from wax esters in a wax-ester rich marine oil.

Calanus finmarchicus is one of the most important zooplankton species in the North Atlantic. The zooplankton is currently being harvested and industrially processed to a marine oil product for human consumption as a marine nutraceutical containing long-chain omega-3 polyunsaturated fatty acids. This oil is very rich in wax esters, a lipid class where fatty acids are esterified to long chain fatty alcohols. In this paper we describe a simple method to 1) isolate the wax esters from the other lipid classes present in the oil, 2) hydrolyze the wax esters, and 3) separate the fatty acids from the fatty alcohol, all by means of solid phase extraction. Starting with an average of 322 mg Calanus oil, we obtained 75 mg fatty alcohols and 63 mg fatty acids. Contrary to previously described techniques, our method neither oxidize the fatty alcohols to fatty acids, nor are the fatty acids methylated, allowing the native, unesterified fatty acids and fatty alcohols to be used for further studies, such as in cell culture experiments to study the metabolic effects of these specific lipid fractions rather than the intact oil or wax esters.

An exclusive kinetics of long chain fatty alcohol oxidation administered by CMC in anionic micellar media and in their binary mixture

This work thrives an organic oxidative transformation of long chain fatty alcohol, decanol, by hexavalent chromium in anionic micellar assisted aqueous medium at 25 °C. The spectrophotometrically studied kinetics of the oxidation has been recorded in a comparative mode in single and mixed micellar media of anionic surfactants (SDSʹ and SDS) of varying chain length. Moreover, another unprecedented comparative kinetic study of promoted (Phen and Bpy promoters) and unpromoted reactions has been shown in both the micellar system. A direct connection of reaction rate with CMC of the surfactants has been shown here. Some necessary spectral analyses (IR and 1H NMR) have been carried out to elucidate the product formation.

Effect of Beeswax on hydrophobicity, moisture resistance and transparency of UV curable linseed oil based coating for compostable paper packaging

Compostable bio-sourced moisture barrier coating is among the most emerging material alternative to non-degradable single use plastics liner in paper packaging applications. In the current work, highly unsaturated linseed oil is epoxidized and acrylated to form UV curable bio-acrylate resin (Acrylated Linseed Oil) to be used as bio-coating material for paper substrate to improve its barrier properties. Beeswax has been proposed as an excellent barrier to water vapour permeability, the hydrophobicity being imparted by esters of long chain fatty alcohols, acids and long chain alkanes present within. Beeswax is incorporated into AELO resin to enhance the water and moisture barrier property of the coating due to its hydrophobicity and food compatibility. The addition of beeswax has significantly reduced the Water Vapour Transmission Rate (WVTR) to 20 g/m2.day.atm while improving the Water Contact Angle (WCA) to 111° for 10 wt% beeswax loading. Further, the WCA remains above 90° even after 50 cycles of abrasion revealing the durability of the coating. The hydrophobicity is further reinstated by the SEM images which show microscale roughness imparted by uniformly dispersed beeswax. Beeswax thus improves hydrophobicity both by virtue of its composition and the surface roughness imparted. Improved transparency (>95% UV–vis transmittance), higher thermal stability (T5 >250 °C, T10 >300 °C), and reasonable glass transition temperature of the bio-coatings reveals its wide application in the field of packaging. The compostability of the coating in soil and paper repulpability after removal of the coating, both explored its potential in paper-based food packaging by replacing single use plastics.

Roles of the MYB94/FUSED LEAVES1 (ZmFDL1) and GLOSSY2 (ZmGL2) genes in cuticle biosynthesis and potential impacts on Fusarium verticillioides growth on maize silks.

Maize silks, the stigmatic portions of the female flowers, have an important role in reproductive development. Silks also provide entry points for pathogens into host tissues since fungal hyphae move along the surface of the silks to reach the site of infection, i.e., the developing kernel. The outer extracellular surface of the silk is covered by a protective hydrophobic cuticle, comprised of a complex array of long-chain hydrocarbons and small amounts of very long chain fatty acids and fatty alcohols. This work illustrates that two previously characterized cuticle-related genes separately exert roles on maize silk cuticle deposition and function. ZmMYB94/FUSED LEAVES 1 (ZmFDL1) MYB transcription factor is a key regulator of cuticle deposition in maize seedlings. The ZmGLOSSY2 (ZmGL2) gene, a putative member of the BAHD superfamily of acyltransferases with close sequence similarity to the Arabidopsis AtCER2 gene, is involved in the elongation of the fatty acid chains that serve as precursors of the waxes on young leaves. In silks, lack of ZmFDL1 action generates a decrease in the accumulation of a wide number of compounds, including alkanes and alkenes of 20 carbons or greater and affects the expression of cuticle-related genes. These results suggest that ZmFDL1 retains a regulatory role in silks, which might be exerted across the entire wax biosynthesis pathway. Separately, a comparison between gl2-ref and wild-type silks reveals differences in the abundance of specific cuticular wax constituents, particularly those of longer unsaturated carbon chain lengths. The inferred role of ZmGL2 is to control the chain lengths of unsaturated hydrocarbons. The treatment of maize silks with Fusarium verticillioides conidia suspension results in altered transcript levels of ZmFDL1 and ZmGL2 genes. In addition, an increase in fungal growth was observed on gl2-ref mutant silks 72 hours after Fusarium infection. These findings suggest that the silk cuticle plays an active role in the response to F. verticillioides infection.

Probing the Role of Connecting Bonds and Modifying Chains in the Rational Design of Prodrug Nanoassemblies.

Prodrug-based self-assembled nanoparticles combined with the merits of nanotechnology and prodrugs strategies have gradually become a research trending topic in the field of drug delivery. These prodrugs usually consist of parent drugs, connecting bonds, and modifying chains. The influences of the connecting bonds and modifying chains on the pharmaceutical characteristics, in vivo delivery fate, and antitumor activity of prodrug nanoassemblies remain elusive. Herein, three docetaxel (DTX) prodrugs were designed using sulfur bonds (thioether bond or disulfide bond) as connecting bonds and fatty alcohols (straight chain or branched chain) as modifying chains. Interestingly, the difference between connecting bonds and modifying chains deeply influenced the colloidal stability, redox responsive drug release, cytotoxicity, pharmacokinetic properties, tumor accumulation, and antitumor effect of prodrug nanoassemblies. DTX conjugated with branched chain fatty alcohols via disulfide bonds (HUA-SS-DTX) significantly improved the antitumor efficiency of DTX and reduced the systematic toxicity. Our study elaborates on the vital role of connecting bonds and modifying chains in the rational design of prodrug nanoassemblies.

Cork Development: What Lies Within.

The cork layer present in all dicotyledonous plant species with radial growth is the result of the phellogen activity, a secondary meristem that produces phellem (cork) to the outside and phelloderm inwards. These three different tissues form the periderm, an efficient protective tissue working as a barrier against external factors such as environmental aggressions and pathogen attacks. The protective function offered by cork cells is mainly due to the abundance of suberin in their cell walls. Chemically, suberin is a complex aliphatic network of long chain fatty acids and alcohols with glycerol together with aromatic units. In most woody species growing in temperate climates, the first periderm is replaced by a new functional periderm upon a few years after being formed. One exception to this bark development can be found in cork oak (Quercus suber) which display a single periderm that grows continuously. Quercus suber stands by its thick cork layer development with continuous seasonal growth. Cork raw material has been exploited by man for centuries, especially in Portugal and Spain. Nowadays, its applications have widened vastly, from the most known product, stoppers, to purses or insulating materials used in so many industries, such as construction and car production. Research on how cork develops, and the effect environmental factors on cork oak trees is extremely important to maintain production of good-quality cork, and, by maintaining cork oak stands wealthy, we are preserving a very important ecosystem both by its biodiversity and its vital social and economic role in areas already showing a population declination.

Preparation, characterization and application of long-chain fatty alcohol-based polymeric micelles

Polymeric micelles have been shown to be promising carriers for drug delivery. However, the present developed micelle carriers are usually based on inert materials, and the potential influence on the body still needs to be further considered. In this work, we synthesized a kind of polymeric carrier based on hydrophobic long chain fatty alcohol (LCFA), which possesses beneficial biological properties for the human body. These polymeric carriers could self-assemble to form micelles with small sizes. Except for MPEG2k–C24, and MPEG2k–C26, other polymeric micelles showed good blood compatibility and high biosafety. In addition, MPEG2k–C28, MPEG2k–C30 and MPEG2k–C32 micelles could efficiently encapsulate paclitaxel (PTX) with about 10% drug loading content and >90% encapsulation efficiency. Overall, our prepared MPEG-LCFA conjugates may have potential clinical application prospects and deserve further research.

Cuban Policosanol Prevents the Apoptosis and the Mitochondrial Dysfunction Induced by Lipopolysaccharide in C2C12 Myoblast via Activation of Akt and Erk Pathways.

Skeletal muscle plays crucial roles in locomotion, protein reservoir, and maintenance of metabolic homeostasis. Loss of muscle, known as muscle atrophy, causes the metabolic diseases such as type 2 diabetes mellitus, hypertension, and so on. Therefore, great efforts have been devoted to prevent the muscle atrophy. Policosanols are a mixture of long chain fatty alcohols extracted from various natural sources. They have long been used as functional foods to lower the level of serum lipids, including triacylglycerol and cholesterol, and to protect against inflammatory stress. In this study, we examine the protective effect and molecular mechanism of Cuban policosanol on skeletal muscle cell death and mitochondrial dysfunction using lipopolysaccharide-treated C2C12 cells. Our results demonstrated that policosanol significantly rescued cell survival (40% vs. 88%; LPS vs. LPS+policosanol) via activation of the Akt pathway, resulting in inhibition of apoptosis (p<0.05). Moreover, policosanol restored the LPS-induced repression of collagen by two fold (0.33±0.04 vs. 0.67±0.03 compared to that of control; LPS vs. LPS+policosanol) via activation of ERK-mTOR-p70S6K pathways. In addition, policosanol increased the mitochondrial fusion by regulating the activities of DRP1 and Mfn2, leading to ameliorate the mitochondrial dysfunction induced by LPS. Improved mitochondria function increased the oxygen consumption rate with glucose as fuel source, indicating that policosanol could shift the glucose metabolism from lactate fermentation, induced by lipopolysaccharide, to oxidative phosphorylation. Thus, policosanol is a promising agent for preventing the inflammation-induced muscle cell death and mitochondrial dysfunction.

GSH/enzyme-responsive 2-sulfonyl-1-methylimidazole prodrug for enhanced transdermal drug delivery and therapeutic efficacy against hyperthyroidis

Novel GSH/enzyme-responsive anti-hyperthyroidism prodrugs designed for transdermal delivery of 2-sulfonyl-1- methylimidazole (MMI) were synthesized by a Michael addition reaction of MMI with propiolic acid (PA) followed by esterification with three long chain fatty alcohols and their structures were characterized by 1H NMR, 13C NMR and mass spectrometry. Their maximum steady state flux through rat skin in the PG/W solution was found to be more than 37-times faster than that of MMI. The result may be attributed to the improved lipophilicity of prodrug and rapid bioconversion. The prodrugs were hydrolyzed by esterase on passing through the skin and appeared mainly as intermediate MMI-PA in the receiver compartment and accompanied by a small amount of MMI and intact prodrug. The prodrugs did not release any MMI in the media without GSH or with 100 µM GSH, while the obvious MMI release could be observed within 6.4 h in the media containing 2 mM and 10 mM GSH, and their maximum cumulative release rates reached 95.07% for lauryl alcohol ester prodrug (MMI-PA-OLa). MMI-PA-OLa exhibited a significant inhibition effect on lactoperoxidase (LPO) after being incubated in millimolar GSH media, whose inhibition rate was very similar to that of free MMI with an equivalent dose. These results suggested that MMI-PA-OLa could pass efficiently through the skin and release MMI in response to the intracellular environment.

Exploring the transportome of the biosurfactant producing yeast Starmerella bombicola

Starmerella bombicola is a non-conventional yeast mainly known for its capacity to produce high amounts of the glycolipids ‘sophorolipids’. Although its product has been used as biological detergent for a couple of decades, the genetics of S. bombicola are still largely unknown. Computational analysis of the yeast’s genome enabled us to identify 254 putative transporter genes that make up the entire transportome. For each of them, a potential substrate was predicted using homology analysis, subcellular localization prediction and RNA sequencing in different stages of growth. One transporter family is of exceptional importance to this yeast: the ATP Binding Cassette (ABC) transporter Superfamily, because it harbors the main driver behind the highly efficient sophorolipid export. Furthermore, members of this superfamily translocate a variety of compounds ranging from antibiotics to hydrophobic molecules. We conducted an analysis of this family by creating deletion mutants to understand their role in the export of hydrophobic compounds, antibiotics and sophorolipids. Doing this, we could experimentally confirm the transporters participating in the efflux of medium chain fatty alcohols, particularly decanol and undecanol, and identify a second sophorolipid transporter that is located outside the sophorolipid biosynthetic gene cluster.

Long-term effects with policosanol on lipid profile according to hypercholesterolemia severity in older patients

Background: End-point based studies have demonstrated a direct relationship between coronary disease and elevated serum levels of low density lipoprotein cholesterol (LDL-C) and total cholesterol, as well as the benefits of lowering LDL-C with statins on clinical end-points. Policosanol is a mixture of very long chain fatty alcohols purified from sugar cane wax, with dislipidemia controlling effects, proved in numerous clinical assays in which patients with different conditions were included. The efficacy and tolerability of policosanol in the elderly have been also investigated in several clinical trials, being effective, safe and well tolerated. Objectives: To investigate the effects of policosanol treatment during three years on lipid profile with a proportional intensity to the initial dislipidemia severity in older hypercholesterolemic patients. Methods: The present analysis was obtained from the data of all patients treated with policosanol included in a previous prevention study. One thousand, ford hundred seventy old patients of both sexes, between 60 to 85 years old, with type II hypercholesterolemia, and ³ 1 non-lipid coronary risk factors, were randomized in two groups and treated with policosanol or placebo, during three years. Significant changes on lipid profile with a proportional intensity to the initial dislipidemia severity were considered primary efficacy variables. The analysis was done by Intention-to-treat method. Results: An analysis of the response intensity show that after treatment, reductions of LDL-C, total cholesterol and triglycerides were greater, and according to the initial hypercholesterolemia severity, so that, patients with severe hypercholesterolemia showed the better responses, followed by moderate and mild hypercholesterolemia. An opposite pattern, however, was observed for HDL-C serum concentration. Triglycerides did not respond in the same way. The frequency of vascular serious adverse events was lower in the policosanol group (15 events) compared with those on placebo group (49 events). There were 109 patients who experienced serious adverse events: 83 (11.3 %) in placebo and 26 (3.5 %) in policosanol group (p&lt;0.0001). Twenty-three deaths occurred up to study completion: 19 patients belonging to placebo group (2.6 %) and 4 to the policosanol group (0.5 %). Conclusions: The treatment with policosanol produce positive changes on serum lipid profile according to hypercholesterolemia severity and with a significant lower amount of vascular serious adverse events, mortality, and frequency of total adverse events in older patients.

Cross Platform Analysis of Volatile Organic Compounds Using Selected Ion Flow Tube and Proton-Transfer-Reaction Mass Spectrometry.

Volatile breath metabolites serve as potential disease biomarkers. Online mass spectrometry (MS) presents real-time quantification of breath volatile organic compounds (VOCs). The study aims to assess the relationship between two online analytical mass spectrometry techniques in the quantification of target breath metabolites: selected ion flow tube mass spectrometry (SIFT-MS) and proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS). The two following techniques were employed: (i) direct injection with bag sampling using SIFT-MS and PTR-ToF-MS and (ii) direct injection and thermal desorption (TD) tube comparison using PTR-ToF-MS. The concentration of abundant breath metabolites, acetone and isoprene, demonstrated a strong positive linear correlation between both mass spectrometry techniques (r = 0.97, r = 0.89, respectively; p < 0.001) and between direct injection and TD tube (r = 0.97, r = 0.92, respectively; p < 0.001) breath sampling techniques. This was reflected for the majority of short chain fatty acids and alcohols tested (r > 0.80, p < 0.001). Analyte concentrations were notably higher with the direct injection of a sampling bag compared to the TD method. All metabolites produced a high degree of agreement in the detection range of VOCs between SIFT-MS and PTR-ToF-MS, with the majority of compounds falling within 95% of the limits of agreement with Bland-Altman analysis. The cross platform analysis of exhaled breath demonstrates strong positive correlation coefficients, linear regression, and agreement in target metabolite detection rates between both breath sampling techniques. The study demonstrates the transferability of using data outputs between SIFT-MS and PTR-ToF-MS. It supports the implementation of a TD platform in multi-site studies for breath biomarker research in order to facilitate sample transport between clinics and the laboratory.

Production of Long Chain Fatty Alcohols Found in Bumblebee Pheromones by Yarrowia lipolytica.

Fatty alcohols (FA-OH) are aliphatic unbranched primary alcohols with a chain of four or more carbon atoms. Besides potential industrial applications, fatty alcohols have important biological functions as well. In nature, fatty alcohols are produced as a part of a mixture of pheromones in several insect species, such as moths, termites, bees, wasps, etc. In addition, FA-OHs have a potential for agricultural applications, for example, they may be used as a suitable substitute for commercial insecticides. The insecticides have several drawbacks associated with their preparation, and they exert a negative impact on the environment. Currently, pheromone components are prepared mainly through the catalytic hydrogenation of plant oils and petrochemicals, which is an unsustainable, ecologically unfriendly, and highly expensive process. The biotechnological production of the pheromone components using engineered microbial strains and through the expression of the enzymes participating in the biosynthesis of these components is a promising approach that ensures ecological sustenance as well. The present study was aimed at evaluating the production of FA-OHs in the oleaginous yeast, Yarrowia lipolytica, with different lengths of fatty-acyl chains by expressing the fatty acyl-CoA reductase (FAR) BlapFAR4 from B. lapidarius, producing C16:0-OH, C16:1Δ9-OH, and lower quantities of both C14:0-OH and C18:1Δ9-OH, and BlucFAR1 from B. lucorum, producing FA-OHs with a chain length of 18–26 carbon atoms, in this yeast. Among the different novel Y. lipolytica strains used in the present study, the best results were obtained with JMY7086, which carried several lipid metabolism modifications and expressed the BlucFAR1 gene under the control of a strong constitutive promoter 8UAS-pTEF. JMY7086 produced only saturated fatty alcohols with chain lengths from 18 to 24 carbon atoms. The highest titer and accumulation achieved were 166.6 mg/L and 15.6 mg/g DCW of fatty alcohols, respectively. Unlike JMY7086, the BlapFAR4-expressing strain JMY7090 produced only 16 carbon atom-long FA-OHs with a titer of 14.6 mg/L.

Triterpenoids and fatty alcohols as indicators of mangrove derived organic matter in Northern Kerala Coast, India

Triterpenoids and fatty alcohols were identified from the sediments of five mangrove ecosystems (Kunjimangalam, Pazhayangadi, Pappinissery, Thalassery, and Kadalundi) in the northern Kerala coast, India, to illustrate the organic matter sources. Straight chain fatty alcohols in the range C12–32 were detected, and among these the long chain fatty alcohols (C20–32) were exclusively even chained compounds. Branched fatty alcohols (6,10,14-trimethyl-pentadecan-2-ol and 3,7,11,15-tetramethyl-2-hexadecanol) of bacterial origin were detected in a few observations. Twenty triterpenoids were detected from the study region in which 13 of them were sterols. Triterpenoids originated from higher plants such as stigmasterol, campesterol, β-sitosterol, taraxerol, lupeol, germanicol, β-amyrin, α-amyrin, and betulin were identified in the study. Brassicasterol, a diatom marker and dinosterol, a dinoflagellates marker were also detected in the study region. An elevated % composition of dinosterol and dissolved oxygen super-saturation were noticed in Kunjimangalam during pre-monsoon, which may suggest elevated input of algal organic matter in the mangrove system. Cholesterol transformation products such as coprostanol and epi-coprostanol were detected, which indicated the presence of fecal contamination in the sedimentary organic matter. From the ternary diagram, it was recognized that the organic matter contribution from marine algae was feeble as compared to terrestrial input.

Supramolecular architecture of a multi-component biomimetic lipid barrier formulation

HypothesisBiomimetic liquid crystalline systems are widely used in skin care cosmetics and topical pharmaceutical preparations. Our ability to rationally design such formulations, however, is hampered by our incomplete understanding of their structure on the nanoscale. ExperimentsUsing polarized light microscopy and small-angle and wide-angle X-ray scattering, the molecular architecture and properties of a barrier formulation prepared from distearoylphosphatidylcholine mixed with long chain fatty acid and alcohols, with and without antimicrobial pentanediols are directly probed. The nature and composition of the phases identified are determined through small-angle neutron scattering studies using chain-deuterated components, and the detailed structure and dynamics of the gel network lamellae are determined through molecular dynamics simulations. FindingsThe formulations show molecular ordering with long and short periodicity lamellar phases and there is little change in these structures caused by changes in temperature, drying, or the application of shear stress. The diol-free formulation is demonstrated to be self-preserving, and the added pentanediols are shown to distribute within the interlamellar regions where they limit availability of water for microbial growth. In culmination of these studies, we develop a more complete picture of these complex biomimetic preparations, and thereby enable their structure-based design.

HetN and patS Mutations Enhance Accumulation of Fatty Alcohols in the hglT Mutants of Anabaena sp. PCC 7120

The heterocysts present in filamentous cyanobacteria such as Anabaena sp. PCC 7120 are known to be regulated by HetN and PatS, the repressors of heterocyst differentiation; therefore, the inactivation of these proteins will result in the formation of multiple heterocysts. To enhance the accumulation of fatty alcohols synthesized in the heterocyst, we introduced mutations of these repressors to increase heterocyst frequency. First, we isolated double mutants of hetN and patS and confirmed that the null mutation of these genes promoted higher frequencies of heterocyst formation and higher accumulation of heterocyst-specific glycolipids (Hgls) compared with its wild type. Next, we combined hetN and patS mutations with an hglT (encoding glycosyltransferase, an enzyme involved in Hgl synthesis) mutation to increase the accumulation of fatty alcohols since knockout mutation of hglT results in accumulation of very long chain fatty alcohol, the precursor of Hgl. We also observed retarded growth, lower chlorophyll content and up to a five-fold decrease in photosynthetic activity of the hetN/patS/hglT triple mutants. In contrast, the triple mutants showed three times higher heterocyst formation frequencies than the hglT single mutant and wild type. The production rate of fatty alcohol in the triple mutants attained a value 1.41 nmol/mL OD730, whereas accumulation of Hgls in the wild type was 0.90 nmol/mL OD730. Aeration of culture improved the accumulation of fatty alcohols in hetN/patS/hglT mutant cells up to 2.97 nmol/mL OD730 compared with cells cultured by rotation. Our study outlines an alternative strategy for fatty alcohol production supported by photosynthesis and nitrogen fixation.